The work of this Center constitutes a multidisciplinary approach; the objectives are to decrease the toxicologic effects of drugs in the neonate and in children, and to increase the effectiveness of drug use by developing analytical methods and new knowledge which will lead to greater clinical capabilities in the treatment of the neonate and children. In the case of neonates, most drugs are acquired through ingestion of drugs by the mother and through drugs administered to the mother at the time of labor and delivery. The drug problems to be studied for children are those encountered in renal-metabolic disorders and in pediatric neurology. The toxic pathway of metabolism which is being studied in greatest detail is the epoxide-diol pathway; epoxides are known to have cytotoxic, mutagenic, carcinogenic or teratogenic properties. It is particularly important that toxicologic effects be studied during the fetal, neonatal and childhood periods while developmental processes are active. These investigations involve collaborative clinical and laboratory work; drug transformations at the subcellular level are also being studied. New analytical methods of high specificity and sensitivity are developed for this work through the use of analytical systems involving mass spectrometry.